Concrete-form



J. C. HAIN.

CONCRETE FORM.

/ APPLICATION FILED JUNE 24.1919.

Patented Oct. 4, 1921. I

Jdnud T; UNITED STATES PATENT OFFICE.

JAMES C. HAIR, OF LOS ANGELES, CALIFORNIA.

CONCRETE-FORM. I

Specification of Letters Patent.

Patented Oct; 4, 1921.

Application filed .Tune 24, 1919. Serial No. 306,444.

T 0 all whom it may concern:

Be it known that I, JAMES C. HAIN, a citizen of the United States,residing at Los Angeles, county of Los Angeles, and State of California,have invented a certain new and useful Concrete-Form, of which thefollowing is a specification.

My invention relates to a means for producing hollow units particularlyfrom plastic material, such as concrete .and other cementitiouscompositions, and it has especial reference to a form for making hollowconcrete block, structural units or parts of buildings. an object of theinvention being to provide a simple and particularly an economicaldevice of light and strong construction, in which the smallest possibleamount of wood or other material may be used.

This and other objects are accomplished by the design illustrated in theaccompanying drawing and showing one of a variety of forms embodying myinvention. Therein Figure 1 is a perspective View of a frame showingpart of the covering adapted therefor, and

Fig. 2 is a plan view showing the form embedded in a concretionary mass.

, My invention relates to that especial art of forming structural unitswhich contemplates the application of the cement, concrete, or otherplastic building material, undcr pressure, but is not restricted in thatrespect, since use of the completed form may be made in the manufactureof building units by other methods.

My invention may comprise a frame 1, that for the purposes of thisspecification may consist of strips 2, preferably heldtogether andspaced by a suitable plate 3. Around the strips 2 of the form is placeda sheathing or covering 4, of any suitable material, as paper, and suchsheathing or covering may be wound spirally about the frame, as shown,and preferably at such a pitch that the convolutions overlap.

In order that the strips 2 of the frame may be held rigid and firmlybonded, so that subsequent swelling thereof shall not cause faults,breakage or cracks in the concrete mass applied thereto, the sheathingor covering 4, may be moistened or otherwise treated previous toapplying the same to the frame, whereby shrinkage, contraction orwarpingof the covering resulting from drying, shall more closely andintimately envelop and bond the strips of the frame, and at the sametime offer suflicient resistance to the concrete or cement when appliedunder pressure.

What I claim, is

1. A form for envelopment by a plastic material comprising a frame woundwith paper.

2. A form for envelopment by a plastic material comprising a framespirally wound with a fibrous material.

3. A form .for envelopment by a'plastic material comprising a framehaving a cover ing shrunk thereon.

4:. A form for envelopment by a plastic material comprising a framehaving a fibrous covering spirally wound and shrunk thereon.

5. A form for making hollow plastic bodies comprising a frame having astrip of paper wound thereabout and shrunk thereon.

6. A. form for' making hollow plastic bodies comprising a frame having afibrous material spirally wound thereabout with the convolutionsoverlapping.

7 A form for making hollow plastic bodies comprising a frame spirallywound with paper previously moistened and shrunk thereon.

8. A core for casting hollow units of plastic material comprising aframe having a flexible covering thereon previously moistened to cause acontraction thereof after application.

In testimony whereof I have set my hand.

J. C. HAIN..

